Shooting ratio
A colleague today, reviewing a video made by some of our students, opened my eyes somewhat:
Even the occasional slightly jarring cut is forgivable when the ratio of footage shot to that used is only about 5:1. (The average feature film is 20:1 while Apocalypse Now was 95:1.)
Wikipedia on shooting ratio.
Wikipedia on Documentary Film — Cinéma vérité and Direct Cinema:
… the shooting ratio (the amount of film shot to the finished product) is very high, often reaching 80:1.

